


Caught in the Fire

by ByTheAngell (SomeLittleInfamy)



Category: Shadowhunters (TV)
Genre: BAMF Magnus Bane, Battle Boyfriends, Canon-Typical Violence, Hurt Alec Lightwood, M/M
Language: English
Status: Completed
Published: 2019-11-16
Updated: 2019-11-16
Packaged: 2021-02-07 09:04:51
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,909
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21455506
Author URL: https://archiveofourown.org/users/SomeLittleInfamy/pseuds/ByTheAngell
Summary: When Shadowhunter weapons aren't working against a new breed of demon, Magnus is called in to assist Alec. But will their personal investment in getting the other out alive be enough motivation to succeed where others failed, or will it be a distraction that could put them both in even more danger in the end?
Relationships: Magnus Bane/Alec Lightwood
Comments: 30
Kudos: 199





	Caught in the Fire

**Author's Note:**

> This idea was co-thought of with [Loren](https://archiveofourown.org/users/drcloyd), who wrote the Alec to my Magnus on a forum RP for a while <3 I loved the idea so much she let me re-work it into a fic, and here we are!

All Magnus told Alec earlier was that he might be a little late because he had a client that evening. It wasn't a lie, though he did decide to leave out the fact that the client was a representative from the Clave, and he definitely left out being warned that whatever they wanted him for was going to be  _ very dangerous _ . Magnus justified this by 1) not really knowing any details about what was needed from him yet, and 2) not wanting to worry Alec when he hadn't even agreed to do it. Whatever ‘it’ was. 

So when he showed up and got the run-down of the exact situation at hand, he knew that it was right in his particular skill set.  This wasn’t the first time Magnus Bane was called on to help the Shadowhunters out with a demon problem, and he was certain it wouldn’t be the last. He did feel a certain thrill with this one though, because the circumstances were unlike anything he encountered before; they were also something the Shadowhunters hadn’t encountered before, either, which was why they turned to him for help. 

Whatever this demon was, it seemed to possess unique abilities beyond that of the average demon. The Nephilim weapons were almost entirely ineffective against it which was when the idea of using magic to combat it came into play.  No wonder they called him in. And after hearing about the previous injuries (and deaths, rest their souls) already suffered in trying to handle things in-house, well, Magnus wasn’t heartless; he couldn't say no and risk someone getting seriously injured, or killed, when he could've been there to stop it. Especially not when he knew Alec would be on the list of people to send out there sooner or later if he didn’t. 

What he didn’t anticipate was Alec being sent on the mission with him. 

“...Magnus? What are you doing here? You didn’t tell me you were visiting, I was just getting ready to head out. ” Alec crossed over to him with a tense half-smile, his attention diverted and his mind already on the mission ahead of him. 

“I know. That’s why I’m here. It looks like we’re on this one together.” 

“No.” Alec’s reply was immediate, the color draining from his skin. Suddenly his previously diverted focus was entirely on Magnus. “Absolutely not. I’ll get another warlock.” 

Magnus winced. “Wow, talk like that and I’ll start to think you don’t have any faith in my abilities.” 

“It isn’t that and you know it. Magnus, this thing is dangerous, you don’t even know the half of it. I don’t want you out there. Just… let me handle this.” Alec insisted. 

“If you think there’s any chance of me letting you go out there with any warlock besides myself…” Magnus shook his head. “Not to sound pretentious, darling, but I’m the best you’ve got and you know it.” 

Alec glared at the ground. Magnus knew that him being right wouldn’t make Alec feel any more at ease over putting him in danger, but Magnus also knew that Alec would always put his duty to protect before his personal feelings. It was normally an annoyance, but in this case it made Alec’s decision that much easier. 

“Fine. Let’s go.” 

\---

“So, what are we looking at here? The guy I spoke to from the Clave gave me a real by-the-book report rundown, but you could tell he hasn’t seen the thing up close.” Magnus asked as they made their way towards the abandoned warehouse on the outskirts of the city that the Shadowhunters managed to trap the demon in. It was kept inside by wards, but they weren’t holding. 

“It’s like a giant octopus, almost. Which is why it’s nearly impossible to deal with - it just sits in the middle of the ground floor, lashing out in every direction with these ridiculously long tentacles.” 

“Of course it is,” Magnus said, rolling his eyes. “Why is it always some kind of horrifying eldritch abomination when you stumble into things, and never something like a small, manageable rabbit-like demon?” This was pretty par for the course from what he could tell after some of Alec’s stories from patrols and missions. Magnus had to wonder how many of them Alec downplayed in the past when they were brought up after a patrol… but he couldn’t worry about that too much just then. 

“It can reach any floor, any door we try to come through, without even trying. And it isn’t stupid, either - it thinks about as fast as it moves. Past two missions most of them could only try with long-range weapons. The few who got close enough to use a seraph blade-” the choked off end of that sentence told Magnus the time for jokes and eye-rolls was over. “But neither had any serious effect.” 

“If I can find a way to bind the tentacles, do you think that’d be enough to get us in there properly to deal with it?” Magnus suggested, watching as Alec’s eyes never stopped scanning their surroundings, constantly alert even though they were still a ways off from the warehouse. 

“Only if your magic has any effect on it. As far as we know you’ll be just as useless as my weapons.” 

“Promising. Alright then. We’ll try the magic first, and hope it works. And if it doesn’t…” Magnus didn’t really want to think about the ‘what if’ scenario of ending up entirely helpless, but he knew it was a possibility, and better to have all the options planned out before they got caught off-guard. 

“If it doesn’t, we get to safe ground and regroup. Maybe they have a cage in Idris we can portal it into, or… I don’t know. Something. The wards aren’t going to hold much longer, and we can’t risk it getting out, or some foolish mundane to try breaking in.” 

Magnus nodded. 

They walked along a little farther until Alec brought his hand up in a fist. Magnus stopped at the signal from Alec, following his gaze toward the windows along the first floor in front of them. He looked carefully, watching the shift of the light behind them in the shadows - there was certainly movement behind them, uneven and large. Just because it seemed contained to the windows along the first level didn't mean it couldn't reach higher, either. If the creature was as dangerous as Alec and his boss described Magnus wasn't about to downplay anything he saw at first glance. 

He didn't like the feeling he got in the pit of his stomach watching the shifting movement from within the building. Could it sense them? Or was it simply restless? 

"I could portal us to the roof, and we could try and catch it off-guard by getting the drop on it from above." Magnus suggested. If the body was confined to the first floor despite the reach of the tentacle, they might get lucky if they didn't approach it from a level it could easily see.

“It’s as good a plan as any. We haven’t tried that yet, and coming in front he ground obviously isn’t working,” Alec admitted reluctantly. 

"One rooftop portal, coming up." Magnus gave Alec what he hoped was a smile that projected a lot more confidence than he actually felt about getting any closer to the building than they already were, especially if all of the weapons Alec had on him were essentially useless. The portal opened in front of them, with Magnus easily keeping the image of the roof in front of them in his mind's eye while he held it open for Alec to step through first, followed by himself. 

It closed behind him on the ground as he stepped through to the rooftop - it was windy, nothing too terrible, but much worse up here than it was on the ground. Magnus looked around them, listening carefully to the sounds of movement from the building below their feet. Was the demon louder than before, like it was moving around more? 

Magnus could practically feel the demonic energy radiate from within the building - this was something stronger than anything he felt outside of Edom before. The signature was entirely unique, it was no wonder Alec's usual weapons weren't having an effect. 

"Be careful," Magnus started, a frown settling onto his face. "The read I'm getting off of this thing is  _ strong _ . And that's with an entire building separating us."

He was careful to walk quietly, shifting his weight and rolling his feet as he walked to avoid any too-heavy steps. His hands were at his sides but they were tense - ready for him to call upon his magic at any moment. They moved as silently as possible down one flight, then another, hearing the thrashing of the demon below them grow louder with each one. 

Magnus followed behind until they were at the doorway to the next floor and he put a hand on Alec's shoulder to stop him. "Let me go first," he said, not as a matter of trying to keep Alec out of harm's way but as a matter of practicality. If the demon was close enough for them to interact with here, if it was visible, Magnus didn't want to worry about hitting Alec if he was standing in front of him. "I'll need a clear shot if it's there." 

He didn't go out blindly, however, opening the door slowly and peering through, listening closely to the much louder sounds of movement, thumps and thrashes that seemed mostly restless and not hostile. Not yet. 

Opening the door all the way it was easy to see the damage caused by the demon in question - parts of the floor had holes broken through them, walls collapsed, and significant structural damage. "This should do," Magnus whispered behind him, taking a cautious step forward into the hallway. As if on cue a black tentacle shot up through the floor several yards in front of them near the middle of the long hallway. Without wasting any time Magnus brought his hands up in front of him, ruby reds and deep crimsons swirling in his palms for just a second before releasing upon the thing snaking its way towards them. His magic hit, and the demon pulled the tentacle back immediately, the black form retreating back through the hole it came out of almost as quickly as it appeared. 

Magnus rushed forward then, looking down, trying to see the damage done. Was it seriously injured? Bleeding? Had he cut a part of it off? Or was it simply surprised, and otherwise unharmed? He couldn't tell for sure without seeing, and thankfully the hole the demon made was plenty big enough to get a good look down...

“Magnus!” 

Magnus heard his name and slowed - he hadn't noticed anything, but he was also so focused on trying to get a good look at the demon that he wasn't looking anywhere else. He felt Alec's hand on his arm and was tugged back as he noticed the slight shift in the floor beneath him. 

A few hurried, stumbling steps backwards got him just clear of the collapsed floor which left an even larger hole where the creature's tentacle burst through. Clearly the integrity of the floor was compromised, and now the two of them stood on the edge of the newly widened hole. He could feel it start to shift again, this time already starting to move before Alec urged them back up to the roof. They started running back towards the door they came in before Magnus thought to open a portal - it would only save them about a minute, but every second counted in moments like this. 

The portal took them both past the remaining two floors to the roof, giving them some extra time to collect themselves. "I think the magic hurt it," Magnus said. "If it was just surprised it would've hit back again before we got out of there - I think I scared it." He couldn't pretend to know for sure, not when he never managed to get a good look at it afterward, but he had a feeling. 

"I could try enchanting your arrows, see if they'll have an effect then." Magnus suggested, aware of the angry sounds from the building which were growing loud enough to hear clearly from the roof now.

Alec, still catching his breath, handed over the arrows without a word. Magnus took the quiver and brought his hands over the arrows, first giving the entire lot of them a once-over with a deep crimson magic before holding each one individually, giving it a little extra of his power within the arrowheads specifically, infusing them with the strongest battle magic he could manage. He had no idea if this would work, or how much it would hold before they could be used, but it was better than nothing. 

Magnus worked quickly, spending no more than a few seconds on each arrow before handing them back to Alec **.** "It knows we're here now - we probably can't catch it by surprise, and if I'm going to kill it with my magic I need to be able to hit something vital - a head, or a heart. I think I might need to go back to the ground floor." 

The holes in the upper floors weren't enough for him to get any sort of clear, steady amount of magic flowing. He knew even as he suggested it that Alec was going to say no and argue. And hell, maybe Alec would have a better idea, but for now it was the best plan Magnus could think of to offer on his own.

As anticipated, Alec shook his head immediately. “Not a chance. You’re not going to the ground floor, not now that it’s pissed off and--” 

Magnus bit his lower lip at the immediate dismissal of the idea. He wasn't going to argue it though - at least not yet. If Alec could think of something else, something better, of course he would be game for it. But he knew it was coming from a place of fear - and he didn't want Alec to make this decision just because he didn't want Magnus to get hurt. Of  _ course _ it was dangerous - this whole thing was dangerous. That's why he was called in in the first place. They both had a job to do here. 

He was about to argue that point when the door behind him burst open violently. Alec already had an arrow loose before Magnus spun around to see the cause: a tentacle shooting out through the space where the door used to be, flinging itself into the space around them on the roof.

Alec's arrow hit and the tentacle drew back, wounded, but it didn't withdraw as the sounds below them grew louder, the movements of the tentacle more violent. Magnus braced himself before shooting another burst of crimson red magic at the tentacle that lashed out towards them - and this time it did pull back, flinging itself wildly to the right in reaction to the hit. He saw smoke coming from where his attack landed - it was definitely hurt but not nearly enough, and it only bought them a second before the tentacle came back toward them with even more force than before. Before it'd been blindly reaching out... after their attacks it knew exactly where they were now.

It all happened so fast. One second they were both focused on the demon's tentacle, launching their attacks and looking for weak spots, and the next it was flinging itself back at them so quickly Magnus barely had time to get out of the way. He fell roughly to the ground which was better than Alec fared, the tentacle catching him square in the middle to push him backwards and away from where Magnus scrambled back to his feet. He watched as Alec tried, and failed, to get an arrow out in time to stop the demon's momentum. 

Magnus went after Alec without a second thought. He used his magic twice, a shot to hurt the demon and another immediately after to try and hold it, to freeze it in place or at least slow it down a little. Both grazed the demon and he heard the cries from within the building grow in shock, or pain, or both, but the tentacle didn’t stop pushing toward the ledge of the roof. 

A moment later the tentacle reached as far as it could and stopped, dropping Alec over the side of the building. 

"No." The word escaped Magnus’ lips in a ragged breath. Magnus ran as fast as he could to close the gap between where he was and the edge of the roof as Alec fell, disappearing from sight. Every step he took felt weighed down by the dread which filled him more and more with every millisecond that passed before reaching the ledge and looking over. Catching sight of Alec immediately Magnus reached out with his magic to try and catch him before he hit the ground, to slow his fall, but before Magnus could see if he made it in time he felt something wrap around his legs and pull them out from under him. 

"ALEXANDER!" Magnus called, not out of fear for his own safety, but wanting - no, _needing _\- to know that he got there in time to stop the fall. But the answer he received was not the one he wanted - the noise he heard echo up to him was faint but there was no denying it was the sound of Alec hitting the ground, an almost imperceptible ‘thump’ that somehow rang deafeningly in Magnus' ears as he was pulled backward into the building by the demon.

Magnus twisted around the best he could as the demon pulled him backwards by his ankle, the tentacle wrapped around his legs several times. They were moving fast, his body bouncing roughly off of walls and stairs as the demon dragged him down one flight, then two, before pulling him through a hole in the floor. He shot at the tentacle several times, the grip around him loosening more and more with each hit of crimson magic he managed to land. It helped but it wasn't enough, and by the time a fourth shot hit and the demon let go he was already tumbling down through another hole in the floor, landing in a pile on the ground of the first floor. 

Magnus heard the crack of his leg hitting the floor before he felt the sharp pain shoot through it, biting on his lip hard enough to draw blood to avoid crying out in a clear display of weakness as he did his best to stand back up. 

Well, getting to the first floor _was_ his plan, after all. It was just helped along a bit, no big deal. 

But he couldn't even keep himself calm with jokes, not while he was staring up at the demon as it loomed over him, tentacles thrashing wildly in the air above his head. He was torn between the obvious need to take down this demon, to fight it and kill it and finish the mission they set out to do, and his much more personal need to find the nearest exit and see if Alec was alright. He didn't know what he would do if he got outside and found--

Magnus didn't get the luxury of thinking about what state he might find Alec in when another tentacle came crashing down at him. Magnus threw himself out of the way, bruising his shoulder as it hit the ground in the least graceful roll he ever executed. That was what he got for allowing himself to grow distracted in his current situation. With multiple tentacles flying towards him he couldn't afford to think about anything other than getting out of here alive. 

Except he also couldn't shake the mental image of Alec falling, of him lying on the ground, injured or unconscious or  _ worse,  _ though he wouldn't even think the word 'dead' despite knowing the chances of any mortal surviving that fall were slim. The rage that filled him at that thought married with the focus he knew he'd need to get out of here in any condition to help Alec which allowed him to respond to the constant barrage of tentacles with rapid releases of magic, hitting each one in turn as it came towards him while weaving in barriers to block when he couldn't dodge fast enough. 

It was no longer about the mission - not as the image of Alec falling replayed over and over in his mind, refusing to grant him a moment of reprieve. This was about revenge now, and Magnus felt a strong, primal instinct begin to take over as fury and self preservation overwhelmed any sense of restraint he had before. His eyes flashed a dangerous slit of golden yellow as he gave into his power entirely in a way he hadn't allowed himself to for centuries. 

Hearing the chilling voice of his father in the back of his head Magnus closed his eyes and focused inward, allowing himself to tap into a reserve of power he’d always been capable of but knew better than to risk unless absolutely necessary. He knew first hand how easily it was to give in to this sort of power and the darkness that came with it if left unchecked: in the past under Asmodeus’ guidance it was a raw power that could level an entire city at its height.

Right now the city was safe, for Magnus’ wrath held a singular focus. 

The demon was able to sense the new surge of power radiating from Magnus, sensed the danger it was now in, and suddenly brought every single one of its tentacles down in Magnus's direction at once with every ounce of force it could muster. It would probably be enough to kill him should he be hit by all of them at once, but Magnus didn't try to run. He didn't move, rooted to the spot, staring up at the exposed underside of the demon as it raised every limb simultaneously before bringing them all down over the warlock. 

It was a sight to behold, and  _ almost  _ a shame no one else was around to witness the display of power, but only  _ almost  _ because if they were they would’ve been obliterated on the spot. 

The reds and blues of his offensive and defensive magic seemed to blend into one and the magic Magnus released next came out of not just his hands but seemingly every inch of him, emitting a pulsing wave of deep purple magic up at the underside of the demon in something akin to a visible magical shockwave. It came from the very core of him and Magnus cried out as he used it, drawing out both the magic and the scream that accompanied it, hands thrust forward to channel the strongest waves of it towards what he hoped was the demon's heart, or core, or  _ whatever fueled this thing _ . 

The demon howled in pain this time, pulling back every tentacle to wrap around itself in agony as Magnus' magic pierced its skin and started to burn it from the inside out. Magnus hadn't known what effect the magic might have when he released it and barely took notice now, only looking to see that he was  _ winning _ . A dangerous line was crossed to get to this point but Magnus knew he couldn't turn back now, so he didn't. He couldn’t think, he wasn’t even entirely aware of the damage he caused as the remaining floors above collapsed around him - the power he tapped into was consuming and all he could do was give in to the need to release it. To destroy. To kill. He didn't stop the magic he drew from within the deepest parts of the power he kept locked away, continuing to yell (which was more of a shriek by this point) into the space in front of him as he attacked, pushing himself until his vision started to go dark at his peripheral and both his breath and his energy left him entirely. 

The demon was hurt. Badly. Mortally, perhaps, but not dead yet. Which was a shame, Magnus realized as he collapsed onto the ground, magic and energy completely spent. Magnus wondered if the demon had enough left it in to kill him now anyway, even after all of that, and as he saw it writhe against the pain of the last of his magic he knew it would only be a matter of time before he got his answer one way or the other.

It was impulsive and reckless and he was loathe to think what might have happened if he didn’t completely exhaust himself here and now… but if it worked it was worth it. And if it didn’t-

Magnus felt the anger and rage fade away with the last of his energy which left him feeling strangely empty in its sudden absence. There was movement to the side of him and for a moment he thought it was the demon again, perhaps one of the tentacles sprung back to life to deal a final blow now that he was too weak to defend himself properly. He closed his eyes for a second, bracing himself for an impact that never came, and he when opened them again a moment later it was to the sound of footsteps as Alec came into the room, limping but moving at as much of a run as he could, bow in hand. 

It was all Magnus could do to watch as Alec released several arrows in succession, each hitting the point where the demon’s tentacles connected to the base of its body, before lunging towards the center of it and plunging the tip of the arrow deep into the demon before landing on the ground next to it. The demon screamed, jolting forward as it’s cry fell silent and all movement ceased. Only then was everything still for the first time since they arrived, leaving an eerie silence to wash over what was such loud, imposing chaos only moments before.

Magnus wanted to move to where Alec was but he couldn't find the strength to push himself up onto his feet. He didn't have to, Alec was coming to him. It looked for a moment as if Alec might be alright but it was clear as the adrenaline wore off and he fell to his knees at the warlock's side that he was far from okay. Several recently activated runes were likely all that kept Alec upright but he was  _ alive _ , and that was all that mattered. 

“Magnus.” The word left Alec’s lips in a breath of relief, reaching a hand out slowly towards Magnus. 

Meeting Alec’s gaze with unglamored yellow cats-eyes Magnus reached out to take Alec's hand in both of his, pulling it close. "Alexander," he said, the word coming out strained between labored breaths. His eyes looked Alec up and down, squeezing onto the hand he held as if to make sure Alec was really there. 

"I was afraid you--" but the sentence choked off as a lump in his throat. Magnus swallowed hard against it. "It pulled me down here before I could get to you." The excuse tumbled out of him, as if some part of him was afraid Alec thought he abandoned him out there to chase the demon inside against Alec's wishes. As if he could _ever_ willingly abandon Alec, injured or otherwise. 

“I’m fine, thanks to you,” Alec sighed, taking a stronger hold of Magnus’ hands before moving from kneeling to sitting down next to him on the floor to rest his own weary, injured body. “Your magic… slowed me down… just in time.” Magnus cringed at how difficult it was for Alec to even string together a full sentence between panting breaths, heart aching at the strain of the wince Alec’s lips pull into, but reminded himself that it could be much, much worse. 

Magnus tried to reach out with his magic, to see if he could heal anything that was wrong with Alec, but there was barely a spark of blue before it faded to nothing at all.

“Magnus, don’t,” Alec protested weakly. “Just rest. I called-” Alec stopped, his words turning into a sputtering cough, wiping the bit of blood it turned up on the back of his hand onto his jeans. “-called backup.” Alec shifted then, laying down next to Magnus on the floor among the dirt and debris to rest himself while they waited. 

With the danger behind them and the mission a success (and most importantly with the knowledge that Alec was (or at least would be) alright) Magnus allowed himself to take Alec’s advice and close his eyes for a moment… which was how their backup would find them, Magnus curled protectively around Alec on the floor of the warehouse, both succumbed to unconsciousness. 

Magnus’ awareness flickered in and out as the Shadowhunters lifted himself and Alec to take them back to the Institute, catching pieces of conversation mixed with horror and awe over the destruction the demon caused. 

Magnus wondered, not without his own fear, how they would react when they realized the worst of it had been him. 

**Author's Note:**

> debating a follow-up where Alec confronts Magnus about losing control and the purple magic, but not totally sure yet. For now it's a one-shot but if you're interested I'd love to know! 
> 
> (Find me on [Tumblr](http://bytheangell.tumblr.com) and also on [Twitter](http://www.twitter.com/By_The_Angell)! <3 )


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